So where are we going now, Home Secretary?

Jack Straw threw cannabis campaigners, the police and politicians into confusion yesterday when he admitted the possibility of a rethink on cannabis - only to reiterate his tough stance on decriminalisation later in the day.

The Home Secretary first hinted at a possible softening of his line on the Today programme on Radio Four when he told John Humphrys that: "If they can prove that this drug is not [dangerous] then of course we will have to think about it again."

The morning after his son William was named as the 17-year-old Cabinet minister's son accused of supplying cannabis to a journalist, Mr Straw asked people and organisations, including this newspaper, to come forward with information. But later, after apparent pressure from Downing Street, he reverted to a hardline stance.

There was further confusion as the existence of secret tapes allegedly recorded by the Mirror emerged last night. Scotland Yard refused to comment.

The Independent on Sunday is to respond to Mr Straw's earlier call for information by handing over a dossier of evidence from leading medical experts and campaigners showing why cannabis should be decriminalised. The research package, which will also contain information on the therapeutic value of cannabis and a petition of 10,000 signatures, is also to be handed to the Police Commission, which has invited this newspaper to give evidence, and to the new drugs tsar, Keith Hellawell, who is to take up his post tomorrow.

The Independent on Sunday editor, Rosie Boycott, said: "We hope that Mr Straw will allow this incident to influence him. He has experienced first-hand what many parents already know - that the vast majority of young people experiment with cannabis. It does not cause them harm. It does not make them criminal. It is time to urgently review the law in this country on cannabis."

Over the past 12 weeks, this newspaper has published material from authoritative sources including leading doctors, psychiatrists and the British Medical Association, which in July voted overwhelmingly for cannabis to be made available for medical use. In a recent editorial, Britain's premier medical journal, The Lancet, wrote: "Cannabis has become a political football ... Sooner or later, politicians will have to stop running scared and address the evidence: cannabis per se is not a hazard to society but driving it further underground may well be."

As the row reverberated around Westminster, the Liberal Democrats and an influential Labour MP yesterday demanded a Royal Commission into the drugs law. Alan Beith, deputy leader and Home Affairs spokesman of the Liberal Democrats, said: "This case illustrates that the best way to tackle drug misuse in our society is to allow a Royal Commission to look at the problem away from the political hothouse at Westminster and the family lives of individual ministers."

David Winnick, a Labour member of the influential Home Affairs select committee, also called for fresh examination of the law. He said: "I am one of those who realise there is a need for a debate on the subject."